Predictors of survival in patients with surgical spine multiple myeloma metastases

Multiple myeloma (MM) is the most common primary malignant tumor of the spine and bone. Spinal metastases are part of the evolution and progression of the MM disease. Therefore, this study aims at investigating prognostic factors associated with overall survival (OS) in patients with symptomatic spine MM metastases.

Consecutive spine surgery procedures were performed in the largest series reported to date and comprising 51 patients with osteolytic vertebral compression fractures resulting from MM, diagnosed by either bone marrow or tumor biopsy.

The mean age of patients was 61.1 years and mean follow-up was 31.9 months. Through univariate analyses, ISS stage (p < 0.0001), preoperative spine instability (SINS score) (p < 0.03), posterior osteosynthesis fixation (p < 0.002), preoperative adjuvant therapy (p < 0.02), postoperative adjuvant treatment (p < 0.001), bone marrow transplant (p < 0.03) and newly MM diagnosed (p < 0.03) emerged as powerful predictors of survival. Cox multivariate proportional hazard model indicated that only ISS Stage and stabilization surgery such as osteosynthesis were two independent predictive factors for OS [hazard ratio (HR): 0.268, 95% confidence interval (CI) 0.07-0.536; p < 0.006 for the former and HR: 0.184, 95% confidence interval (CI) 0.03-0.89; p < 0.04 for the latter].

Stabilization surgery combined to ISS staging should be considered as an important prognostic survival factor for patients with symptomatic MM spine metastases.